Drawing your background with Javascript

Having complex backgrounds (like radial gradients) or even dynamic backgrounds in a web page is not an easy task using only images. Javascript helps here and the SVG/VML support in modern browsers makes drawing a reality. Looking around in the Javascript library world there are some which have APIs for crossbrowser drawing or charting. But if you are looking for a small and easy to learn on you have to search. We found raphaeljs, a project which started as a 20%er at Atlassian. It has an API which is close to SVG but also supports non SVG browsers like IE. How to make animations and complex drawings is easy to learn. The examples give a hint of what is possible.
We needed a radial gradient to have a smooth background, looking at the docs and the SVG spec, it was a four liner:

var Paper = Raphael("canvas", width, height);
var b = Paper.circle(width / 2, height / 2, Math.max(width, height));
var gradient = {type: "radial", dots: [{color: "#FFFFFF"}, {color: "#D5D5D5"}], vector: [0, 0, 0, "100%"]};
b.attr({"gradient": gradient});

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s